Chronic recurrent multifocal osteomyelitis (CRMO) is a systemic aseptic ostheoarticular inflammatory disorder of unknown origin. It occurs mainly in children and adolescents; commonly affects tubular bones and the clavicle, and, less frequently, the spine and pelvic bones.
We describe the case of a previous healthy ten-year-old girl that was admitted to our hospital due to severe lumbar pain over the last five days, without fever or other symptoms. The inflammatory markers and the immunological, microbiological and tumoral studies were normal. Spinal MR imaging scans showed non-specific lesions at L5 and S1 vertebral bodies; therefore, bone biopsy local specimens were obtained and revealed inconclusive inflammatory lesions with microabscess and granulomatous foci. Four months later, and after a transitory symptom relief period, she presented with left gonalgic pain and scoliosis. New imagiology demonstrated regression of previous spine lesions and exacerbation of the right sacral lesion; there were no other articular or bone changes. Bone scintigraphy illustrated hyper fixation foci at left hip articulation and right sacroiliac area. No changes were documented on Leukoscan and Electromyography.
This prolonged and fluctuant symptom course in childhood, with normal analytical studies and non-specific histological and radiological lesions, is strongly suggestive of CRMO. After initiation of anti-inflammatory therapy (indomethacin), she underwent progressive clinical improvement.
The authors aim to call the attention to the fact that the CRMO is an exclusion diagnosis which is frequently misdiagnosed. A high index of suspicion is essential in order to diagnose CRMO and thus to avoid unnecessary diagnostic procedures before the appropriate treatment is initiated.